Apparatus and method for recycling blackwater and greywater at oil and gas well sites

ABSTRACT

A bioreactor for a water treatment system includes a tank configured to receive an influent liquid, a separator structure positioned in the tank, the separator structure having a frustoconical shape and defining a downwardly-facing opening proximal to or at a bottom of the separator structure, an interior of the separator structure being in communication with the tank, external to the separator structure, at least via the opening, an aeration vent positioned proximal to a bottom of the tank and configured to direct air into the tank, but not directly into the interior of the separator structure, and an effluent outlet communicating with the interior of in the separator structure, proximal to a top of the separator structure, a relatively clean effluent liquid, in comparison to the influent liquid in the tank, exiting from the separator structure via the effluent outlet.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Patent Application havingSer. No. 16/879,250, which was filed on May 20, 2020 and is continuationof U.S. Patent Application having Ser. No. 16/007,495, which was filedon Jun. 13, 2018 and claims priority to U.S. Provisional PatentApplication having Ser. No. 62/519,692, which was filed on Jun. 14,2017. Each of these priority applications is incorporated herein byreference in its entirety.

BACKGROUND

Clean water used by personnel performing labor at oil and gas well sitesis commonly delivered and stored in water tanks at the well site. Wateris also needed at well sites during drilling operations for drillingfluid, also called drilling mud. The purchase, delivery, and storage ofwater at well sites can be a significant part of overhead associatedwith drilling operations.

Many tasks and operations at oil and gas well sites, including drillingoperations, require human labor. The presence of personnel at the wellsite and their water needs may vary. Most if not all personnel at wellsites require the use of on-site restrooms. Personnel residing at wellsites over multiple days require running water for drinking, cooking,cleaning dishes, and washing clothes. Consequently, human activity atoil and gas well sites commonly results in at least two types ofwastewater: blackwater and greywater.

Blackwater results from restrooms and is wastewater containing feces,urine and flushwater from flush toilets or toilet paper. Greywater orsullage is generally wastewater generated in households or officebuildings from streams without fecal contamination, i.e. all streamsexcept for the wastewater from toilets. Greywater may include thewastewater resulting from cleaning dishes and washing clothes.Blackwater and greywater are to be distinguished from “produced water,”which term is used in the oil industry to describe water that isproduced as a byproduct along with the oil and gas.

Generally, blackwater and greywater resulting from human activity cannotsimply be disposed of at an oil or gas well site; rather, industrypractice has been to collect the wastewater in holding tanks and thentransport it to remote locations for treatment. Often municipal watertreatment facilities are contracted to receive and treat blackwater andgreywater. The cost for wastewater transport services and to compensatemunicipal wastewater treatment facilities can significantly increaseoverhead for well site operations.

There are a number of challenges with collecting and treating blackwaterand greywater. Treatment of such wastewater has often had to rely onmunicipal water treatment facilities or other more permanent watertreatment systems. Such facilities may be permanently located at greatdistances from remote well sites. Further, the water treatmentfacilities are generally not built for specific well sites or groups ofwell sites because of the extensive resources and costs to build them.Likewise, the tentative viability of well sites and scarcity of wellsites in a given group to be served make it infeasible to buildpermanent water treatment facilities for specific well sites or groupsof well sites. Once a water treatment facility is built, it is usuallyfixed to a location and cannot be transported to new sites when needed.

Also, greywater from certain greywater sources at well sites containssubstantial amounts of diesel, oil, grease, cuttings, and or drillingmud. Some of these contaminants, such as diesel, kill or otherwiseinhibit growth of bacteria and other microorganisms useful for thetreatment of waste water.

SUMMARY

A bioreactor for a water treatment system is disclosed. The bioreactorincludes a tank configured to receive an influent liquid, a separatorstructure positioned in the tank, the separator structure having afrustoconical shape and defining a downwardly-facing opening proximal toor at a bottom of the separator structure, an interior of the separatorstructure being in communication with the tank, external to theseparator structure, at least via the opening, an aeration ventpositioned proximal to a bottom of the tank and configured to direct airinto the tank, but not directly into the interior of the separatorstructure, and an effluent outlet communicating with the interior of inthe separator structure, proximal to a top of the separator structure, arelatively clean effluent liquid, in comparison to the influent liquid,exiting from the separator structure via the effluent outlet.

A water treatment system is also disclosed. The water treatment systemincludes a bioreactor including a tank configured to receive an influentliquid, a separator structure positioned in the tank, the separatorstructure having a frustoconical shape and defining a downwardly-facingopening proximal to or at a bottom of the separator structure, aninterior of the separator structure being in communication with thetank, external to the separator structure, at least via the opening, anaeration vent positioned proximal to a bottom of the tank and configuredto direct air into the tank, but not into the interior of the separatorstructure, and an effluent outlet communicating with the interior of inthe separator structure, proximal to a top of the separator structure, arelatively clean effluent liquid, in comparison to the influent liquid,exiting from the separator structure via the effluent outlet, a filtertank in fluid communication with the second clarifier, an ultraviolet(UV) filter in fluid communication with the filter tank, and achlorinator in fluid communication with the UV filter.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may best be understood by referring to thefollowing description and accompanying drawings that are used toillustrate embodiments of the invention. In the drawings:

FIG. 1 illustrates a flow diagram of a wastewater treatment system,according to an embodiment.

FIGS. 2A and 2B illustrates a plan view and an elevation view,respectively, of the wastewater treatment system, according to anembodiment.

FIG. 3 illustrates a perspective view of a container in which thewastewater treatment may be housed, according to an embodiment.

FIG. 4 illustrates a perspective view of a bioreactor tank, according toan embodiment.

FIG. 5 illustrates a side, elevation view of a conical clarifier,according to an embodiment.

FIG. 6 illustrates a side, cross-sectional, conceptual view of thebioreactor tank including the conical clarifier, according to anembodiment.

FIGS. 7A and 7B illustrate a flowchart of a method for treatingwastewater, according to an embodiment.

DETAILED DESCRIPTION

The following disclosure describes several embodiments for implementingdifferent features, structures, or functions of the invention.Embodiments of components, arrangements, and configurations aredescribed below to simplify the present disclosure; however, theseembodiments are provided merely as examples and are not intended tolimit the scope of the invention. Additionally, the present disclosuremay repeat reference characters (e.g., numerals) and/or letters in thevarious embodiments and across the Figures provided herein. Thisrepetition is for the purpose of simplicity and clarity and does not initself dictate a relationship between the various embodiments and/orconfigurations discussed in the Figures. Moreover, the formation of afirst feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed interposing the first and secondfeatures, such that the first and second features may not be in directcontact. Finally, the embodiments presented below may be combined in anycombination of ways, e.g., any element from one exemplary embodiment maybe used in any other exemplary embodiment, without departing from thescope of the disclosure.

Additionally, certain terms are used throughout the followingdescription and claims to refer to particular components. As one skilledin the art will appreciate, various entities may refer to the samecomponent by different names, and as such, the naming convention for theelements described herein is not intended to limit the scope of theinvention, unless otherwise specifically defined herein. Further, thenaming convention used herein is not intended to distinguish betweencomponents that differ in name but not function. Additionally, in thefollowing discussion and in the claims, the terms “including” and“comprising” are used in an open-ended fashion, and thus should beinterpreted to mean “including, but not limited to.” All numericalvalues in this disclosure may be exact or approximate values unlessotherwise specifically stated. Accordingly, various embodiments of thedisclosure may deviate from the numbers, values, and ranges disclosedherein without departing from the intended scope. In addition, unlessotherwise provided herein, “or” statements are intended to benon-exclusive; for example, the statement “A or B” should be consideredto mean “A, B, or both A and B.”

FIG. 1 illustrates a flow diagram of a wastewater treatment system 100,according to an embodiment. The system 100 may receive a primary (e.g.,blackwater or graywater) wastewater stream (“influent fluid”) from aprimary source 101. The primary influent fluid may be received fromsources that are generally considered to be free from contaminants thatare known to kill or negatively impact growth of useful bacteria in thewater treatment process (e.g., hydrocarbons such as diesel, acids,bleach, etc.). The primary source 101 may include greywater from most orall greywater sources, including from all washing machines, dishwashers,showers, sinks, etc., other than the secondary or designated greywatersource, in general, so long as the greywater sources are maintainedgenerally free from the aforementioned contaminates.

The primary influent fluid may be directed to a pre-clarifying assembly102, which may include a first settling tank for receiving waste water,and an influent water tank, among potentially other structures. Oneexample of the first settling tank may include dimensions for holdingabout 1,000 gallons, 1,250 gallons, or 1,500 gallons of water. The firstsettling tank may include an outlet that is configured to acceptinfluent from a point along the height of the first settling tank,proximal to the top, such that relatively clean influent is taken,rather than solids, which have settled to the bottom, or floatingcontaminants on the top. Fats and oils from waste water in the firstsettling tank rise toward the top of the water and cleaner water fromthe middle section of the first settling tank is removed and transferredto an influent tank using gravity transfer.

A baffle having holes or slots to permit the passage of water isdisposed horizontally within the first settling tank approximatelyadjacent to a region just below the middle region of the first settlingtank. The baffle facilitates reduction of water movement between themiddle region of the first settling tank where clarified wateraggregates and the lower region of the first settling tank where solidscan settle and accumulate. The baffle disposed in the first settlingtank helps separate settled dirty water from middle clarified orpartially clarified water. The first settling tank also includes a waterconduit or pipe, which can be made of PVC, configured for transferringclarified or partially clarified water from the first settling tank. ThePVC pipe or conduit is fluidly connected to the effluent port on theinside of the first settling tank and extends approximately halfway intothe first settling tank in the middle region of the tank where theclarified or partially clarified water resides. An opening near the endof the PVC pipe at the middle region of the first settling tank allowsclarified water to exit the first settling tank through the PVC pipe.Clarified water traveling through the PVC pipes passes through theeffluent port and into flexible rubber hose that couples the firstsettling tank with the influent tank. As water is pumped into the firstsettling tank, hydraulics force clarified water through the PVC pipe,the effluent port, and the flexible rubber hose so that the clarified orpartially clarified water transfers into the influent tank.

The influent tank may also made of a light polycarbonate plastic and isused for holding water received from the first settling tank untilsufficient water has been received for delivery to the bioreactor tank.The influent tank can be a doorway tank which can be configured with arange of dimensions for holding water ranging from about 50 gallons toabout 500 gallons of water. In an embodiment, the influent tank is a250-gallon doorway tank. The influent tank may be configured with afloat-switch that triggers a pump when the water level reaches a desiredlevel in the influent tank. When water diminished of fats and oilsreaches a desired level in the influent tank, the float-switch triggersthe influent tank pump, and water is pumped from the influent tankthrough water conduits into a bioreactor tank configured for combinedaeration and clarifying.

As mentioned above, the influent fluid received from the influent tankmay be directed to the bioreactor tank (also referred to herein as abioreactor) 104, which may include a combination of a conical clarifier106 and an aerator tank 105. In particular, the conical clarifier 106may be positioned within the aerator tank 105, as will be described ingreater detail below. The bioreactor tank 104 is configured withappropriate dimensions for increased water surface area to reduce therate at which water levels change. The bioreactor tank is a verticaltank made of a light polycarbonate plastic polymer configured with arange of dimensions for holding water ranging from about 1,000 gallonsto about 1,700 gallons of water. Further, the mixed liquor (activatedsolids and fluids) in the bioreactor tank 104 may be held at a pHbetween about 7 and about 8. Further, the dissolved oxygen levels in themixed liquor in the aerator tank 105 may range from about 1 mgL to about5 mgL.

Solids settleability characteristics within the aerated mixture in thebioreactor tank 104 can be measured using a settleability test. A15-minute settleability test can be run using a (e.g., 1,000 mL) beaker.The bioreactor 104 may be properly operated where settlementmeasurements are between about 150 mgL and 600 mgL. In an embodiment,the optimal settlement level measured by the 15 minute settleabilitytest is between about 200 mgL and 300 mgL when other parameters arewithin optimal ranges. The settlement level range may fluctuatedepending on bioreactor water temperatures. Bio-augmentation nutrientlevels will vary depending on the life forms seen under the microscope.

Water in the bioreactor tank may be maintained at between 70 and 95degrees Fahrenheit to promote bacteria growth. The water temperaturewithin the bioreactor tank 104 can be moderated in several ways. Waterheaters with thermal controls can be disposed within the water in thebioreactor tank 104. Likewise, air temperature within the insulatedmetal storage shipping container can be moderated, which in turn helpscontrol or buffer the water temperature within the bioreactor tank 104.Air temperature within a container in which the bioreactor tank 104 isheld (discussed below with reference to FIG. 3) may be controlled usingportable air conditioning or heating units with thermal controls.

The bioreactor tank 104 may include an effluent outlet, which removesrelatively clean effluent fluid (as compared to the influent fluid) fromwithin the conical clarifier 106, and directs the effluent fluid to asecond clarifier 108, and then to a post-clarifying assembly 110. Aswill be described in greater detail below, the post-clarifying assembly110 may include one or more filter tanks, chlorinators, ultraviolet (UV)filters, transfer tanks, pumps, etc. After passing through thepost-clarifying assembly 110, the effluent fluid may be pumped into awastewater tank 112. The effluent fluid in the wastewater tank 112 maythen be combined with wastewater from a secondary source 114 for use inoil rig operations, such as drilling fluid, boiler water, pressurewashing fluid, etc.

In some embodiments, the secondary source may be greywater that ispotentially contaminated with hydrocarbons or other compositions thatmay harm bacteria, e.g., in the bioreactor tank 104, and is thus nottreated through the system 100 with the influent fluid from the primarysource 101. As such, greywater processing is separated so that greywaterfrom a primary source may be treated separately from a secondary ordesignated greywater source. The secondary or designated greywatersource includes waste water from a designated washer for washing righands' clothes and materials soiled with contaminants that can kill orinhibit growth of useful bacteria and other microorganisms. Thegreywater from the secondary or designated greywater source may includesubstantial amounts of diesel, oil, grease, cuttings, and or drillingmud.

Turning now to FIGS. 2A and 2B, there is shown a plan view and anelevation view, respectively, of the wastewater treatment system 100,according to an embodiment. As shown, the system 100 includes thebioreactor tank 104. FIGS. 2A and 2B also depict additional elements ofthe post-clarifying assembly 110, namely, in this embodiment, a secondclarifier 200, a filter tank 202, a UV filter 204, a chlorinator 206, atransfer tank 208, and a wastewater tank 210. In a specific embodiment,the post-clarifying assembly 110 also includes one or more flexiblepipes (e.g., pipe 212), which connect the elements together,facilitating the mobility of the system 100.

The second clarifier 200 may be a vertical tank made of a lightpolycarbonate plastic polymer. The second clarifier 200 may beconfigured with a range of dimensions for holding between about 300 andabout 500 gallons of water. The inside bottom of the second clarifier200 may be cone-shaped and funnel toward the center where a solidsremoval port is disposed. Solids settled in the second clarifier 200 maybe removed from the tank by via the solids removal port.

Water clarified in the second clarifier 200 may be conveyed usinggravity and/or hydraulics through water conduits to the filter tank 202,which may be a gravity filter tank 202. The gravity filter tank 202 maybe a vertical tank made of a light and durable polycarbonate plastic.The inside bottom of the gravity filter tank 202 may be cone-shaped andfunnel toward the center where a solids removal port is disposed. Solidsaccumulating in the bottom of the gravity filter tank 202 may be removedfrom the tank through the solids removal port. The gravity filter tank202 may be configured with a range of dimensions for holding frombetween about 40 and about 100 gallons of water. The gravity filter tank202 may use various filter media. Crushed pumice works may be employedas the gravity filter media for removing residual particles withoutclogging the gravity filter. It is understood that other filter mediasuch as sand or GAC could also be used in the gravity filter tank 202.

The transfer tank 208 may be a cylindrical vertical tank and is made ofa light and durable polycarbonate plastic. The transfer tank 208 may beconfigured with a range of dimensions for holding from about 200 gallonsand 350 gallons of water. The transfer tank 208 may be configured with afloat-switch that triggers a pump when the water level reaches a desiredlevel in the transfer tank. Water is then pumped from the transfer tank208 to a rig tank or day tank. Treated water conveyed from the transfertank 208 to the rig tank or day tank can then be used for otheroperations at the well site, such as drilling operations, pressurewashing the rig, or for boilers to heat the rig. The rig tanks/day tanksmay hold from about 40,000 gallons to about 80,000 gallons of water.

The system 100 may also include a freshwater holding assembly 250, whichmay include filters, pumps, tanks, etc., as desired. However, thefreshwater holding assembly 250 may not be in direct communication withthe other elements of the system 100. In particular, the system 100,including the freshwater holding assembly 250 may be conveniently storedand mobile within a container, such as the container 350 shown in FIG.3, along with at least some of the other tanks of the system 100.

Typically, water treatment systems in oil rigs may include multiple suchcontainers; however, rig area is valuable. Embodiments of the presentsystem 100 may fit in a single container 350, not only increasingmobility, but also minimizing the footprint of the system 100. In anembodiment, the container 350 may be metal, and configured as a standardshipping container. The internal storage area of the metalstorage/shipping container 350 may be divided so that there is an areadevoted to the storage and transfer of fresh water (e.g., clean watertransported to the well site for use by well site personnel), and anarea devoted to the primary and secondary segments of the watertreatment system. The area within the metal storage container devoted tothe primary and secondary segments of the water treatment system mayextend approximately 24 feet along the length of the inside of the metalstorage container and be divided by a wall configured between the watertreatment area and the fresh water storage area. The fresh water storagearea is disposed on the other side of the wall within the storagecontainer opposite the water treatment area. The fresh water storagearea may extend approximately twenty feet along the length of the insideof the storage container on the other side of the wall opposite thewater treatment area.

A plurality of polycarbonate plastic water tanks are disposed within thewater storage area. For example, four fresh water tanks may be disposedin the fresh water storage area with each tank having dimensions ofabout 88 inches high by about 88 inches long by about 44 inches wide.Further, the first settling tank may be disposed outside of the metalstorage container adjacent to the influent water tank.

FIG. 4 illustrates a perspective view of the bioreactor tank 104,showing the aerator tank 105 and the conical clarifier 106 positionedtherein. The bioreactor tank 104 may include an inlet port 405, whichmay be offset from the conical clarifier 106, so as to avoid influentbeing received directly from the inlet port 405 to the interior of theconical clarifier 106.

The conical clarifier 106 is relatively small in comparison to theaerator tank 105. In some embodiments, the conical clarifier 106occupies no more than ⅛^(th) of the volume of the aerator tank 105.Moreover, FIG. 4 illustrates the aerator tank 105 as being clear, and insome embodiments, it is made of a clear or translucent polymer material(e.g., polycarbonate), which provides a quick reference as to theoperating state of the bioreactor tank 104. Indeed, any of theaforementioned tanks discussed herein may be fabricated using a clearpolymer. In other embodiments, the bioreactor tank 104 (and/or any ofthe other tanks discussed herein) may be made from an opaque material,such as fiberglass, other polymers, composites, metal, etc.

The aerator tank 105 may include an aeration assembly, and inparticular, a plurality of aerator vents 400 connected together via oneor more air lines 402 which may be configured to receive air, e.g.,compressed air, from an air source. As shown, the aerator vents 400 maybe diffusers, configured to disperse air received therein. Further, theaerator vents 400 may be positioned at or proximal to a bottom 404 ofthe aerator tank 105, e.g., below the level of the conical clarifier106. However, the aerator vents 400 may not be positioned directly underthe bottom 410 of the conical clarifier 106, so as to avoid sending airinto the bottom 410 of conical clarifier 106, which may be open orotherwise in fluid communication with the aerator tank 105.

The bioreactor tank 104 may further be provided with a support stand 420for supporting the conical clarifier 106 in the aerator tank 105. Thestand 420 may be made from tubular members (e.g., PVC pipes) joinedtogether to hold the conical clarifier 106 at a prescribed height. Forexample, the conical clarifier 106 may be held such that its top 412 isslightly above the maximum fluid line of the aerator tank 105.

As can also be seen in FIG. 4, the conical clarifier 106 may include aneffluent outlet 430. The effluent outlet 430 may extend into the side ofthe conical clarifier 106, e.g., between the bottom 410 and the top 412of the conical clarifier 106. Additional details regarding embodimentsof the effluent outlet 430 are discussed below.

FIG. 5 illustrates a side, elevation view of the conical clarifier 106,according to an embodiment. As shown, the conical clarifier 106 issupported on the stand 420. Further, as shown, the conical clarifier 106may be truncated at its bottom 410, rather than coming to a point. Thetruncated bottom 410 may include an opening, such that the interior ofthe conical clarifier 106 is in fluid communication with the surroundingaerator tank 105 (e.g., FIG. 4).

Further, the effluent outlet 430 is shown, extending through the side ofthe conical clarifier 106. As can be seen, the effluent outlet 430includes an upwardly-turned end 500. The upwardly-turned end may beconfigured to be received into a weir, so as to prevent floating debrisfrom exiting the conical clarifier 106.

FIG. 6 illustrates a simplified, side, cross-sectional view of thebioreactor tank 104, according to an embodiment. As shown, influent isdeposited into the aerator tank 105 via an inlet 600. The aerator vents(e.g., diffusers) 400 are positioned along the bottom 404 of the aeratortank 105, but are not positioned directly below the bottom 410 of theconical clarifier 106. As such, air bubbles emanating from the vents 400are directed into the aerator tank 105, to agitate the influent andpromote bacteria activity, but may not be directed to the bottom 410.This may prevent the bubbles, which are generally intended to agitatethe fluids in the aerator tank 105, from agitating the fluid in theconical clarifier 106, despite a downwardly-facing opening 610 extendingthrough the bottom 410 of the conical clarifier 106.

FIG. 6 also illustrates a lateral opening 620 extending through thesidewall of the conical clarifier 106. The lateral opening 620 allowsfor ingress of influent from the aerator tank 105 directly into theconical clarifier 106. Further, a weir 630 is provided, as mentionedabove, surrounding the upwardly-turned end 500 of the effluent outlet430. As shown, the weir 630 may be tubular and may extend downwardly,past the surface of the fluid in the conical clarifier 106, so as toprevent floating debris from entering the effluent outlet 430.

In operation, the agitated, aerated influent in the aerator tank 105communicates with the interior of the conical clarifier 106 by way ofthe lateral opening 620. Within the conical clarifier 106, the influentis generally held quiescent, allowing for gravity-based separation ofentrained solids 650 from the effluent fluid 660. The effluent fluid 660drains, e.g., by operation of gravity, around the weir 630 and into theeffluent outlet 430, for movement to the post-clarifying assemblydiscussed above. The solids 650 may drop through the downwardly-facingopening 610 and back into the aerator tank 105, or may remain in theconical clarifier 106.

FIG. 7 illustrates a flowchart of a method 700 for treating wastewater,according to an embodiment. The method 700 may proceed by operation ofone or more embodiments of the system 100 discussed above, but in otherembodiments, may be executed by one or more other systems. Furthermore,the steps of the method 700 may be executed in an order other than whatis shown, or the various steps may be combined, separated, or done inparallel without departing from the scope of the present disclosure.

The method 700 may begin by receiving an influent fluid into an aeratortank 105 from a primary influent source 101, as at 702. However, theinfluent fluid may be received at one or more pre-processingtanks/structures, as desired, prior to being received into the aeratortank 105. The method 700 may further include aerating the aerator tank105 using a plurality of aerator vents 400 positioned proximal to abottom 404 of the aerator tank 105, as at 704. The aerator vents 400 maybe or include diffusers positioned along the bottom 404 of the aeratortank 105, and may not be positioned directly below the conical clarifier106.

The method 700 may also include receiving at least some of the influentfluid into a conical clarifier 106 positioned within the aerator tank105, as at 706. In some embodiments, the aerator vents 400 areconfigured to not direct air to a bottom of the conical clarifier 106.Further, receiving the influent fluid into the conical clarifier 106 mayinclude receiving the at least some of the influent fluid through alateral opening 620 in the conical clarifier 106 that is positionedbetween a bottom 410 and a top 412 of the conical clarifier 106.

The method 700 may further include separating the influent fluid in theconical clarifier 106 by gravity to generate an effluent fluid 660 and asolid waste 650, as at 708. The solid waste 650 may sink to the bottom410 of the conical clarifier 106. The effluent fluid 660 may be directedto an effluent outlet positioned within the conical clarifier, as at710. Directing the effluent fluid 660 to the effluent outlet 430 mayalso include using a weir 630 that surrounds the effluent outlet 430 toprevent floating sewage from entering the effluent outlet 430.

In some embodiments, the method 700 may also include directing theeffluent fluid from the effluent outlet to a second clarifier, as at720. The method 700 may further include directing the effluent fluidfrom the second clarifier to a filter tank, as at 722. The method 700may also include directing the effluent fluid from the filter tank to anultraviolet (UV) filter, as at 724. The method 700 may further includesterilizing the effluent fluid using the UV filter, as at 726. Themethod 700 may additionally include chlorinating the sterilized effluentfluid using an in-line chlorinator, as at 728. The method 700 mayfurther include directing the sterilized, chlorinated effluent to atransfer tank, as at 730, and pumping the sterilized, chlorinatedeffluent into a wastewater tank, as at 732. In some embodiments, theeffluent fluid may not be pumped between the effluent outlet and thetransfer tank, but may be moved by gravity.

The method 700 may further include receiving a secondary flow ofwastewater from a secondary source 114 that is contaminated withcontaminant that would inhibit bacteria activity in the aerator tank 105(e.g., hydrocarbons or bleach), as at 734, and combining the secondaryflow of wastewater with the sterilized, chlorinated effluent downstreamfrom the wastewater tank 112, as at 736.

The method 700 may also include positioning the aerator tank 105 and theclarifier 106 into a mobile container 350, as at 738. The method 700 mayalso include positioning a freshwater holding assembly 250 that is notin fluid communication with the aerator tank 105 into the mobilecontainer 350, as at 740, and moving the mobile container with theaerator tank and clarifier and the freshwater system positioned therein,as at 742.

As used herein, the terms “inner” and “outer”; “up” and “down”; “upper”and “lower”; “upward” and “downward”; “above” and “below”; “inward” and“outward”; “uphole” and “downhole”; and other like terms as used hereinrefer to relative positions to one another and are not intended todenote a particular direction or spatial orientation. The terms“couple,” “coupled,” “connect,” “connection,” “connected,” “inconnection with,” and “connecting” refer to “in direct connection with”or “in connection with via one or more intermediate elements ormembers.”

The foregoing has outlined features of several embodiments so that thoseskilled in the art may better understand the present disclosure. Thoseskilled in the art should appreciate that they may readily use thepresent disclosure as a basis for designing or modifying other processesand structures for carrying out the same purposes and/or achieving thesame advantages of the embodiments introduced herein. Those skilled inthe art should also realize that such equivalent constructions do notdepart from the spirit and scope of the present disclosure, and thatthey may make various changes, substitutions, and alterations hereinwithout departing from the spirit and scope of the present disclosure.

What is claimed is:
 1. A bioreactor for a water treatment system, thebioreactor comprising: a tank configured to receive an influent liquid;a separator structure positioned in the tank, the separator structurehaving a frustoconical shape and defining a downwardly-facing openingproximal to or at a bottom of the separator structure, wherein aninterior of the separator structure is in communication with the tank,external to the separator structure, at least via the opening; anaeration vent positioned proximal to a bottom of the tank and configuredto direct air into the tank, but not directly into the interior of theseparator structure; and an effluent outlet communicating with theinterior of in the separator structure, proximal to a top of theseparator structure, wherein a relatively clean effluent liquid, incomparison to the influent liquid, exits from the separator structurevia the effluent outlet.
 2. The bioreactor of claim 1, furthercomprising an aeration line connected to the aeration vent, wherein theaeration line extends along a bottom of the tank.
 3. The bioreactor ofclaim 2, wherein the aeration line extends through a wall of the tank,proximal to the bottom of the tank.
 4. The bioreactor of claim 1,wherein the aeration vent comprises one or more diffusers extending fromthe bottom of the tank.
 5. The bioreactor of claim 1, further comprisinga stand having a base configured to receive the separator structure,wherein the stand is supported on a bottom of the tank.
 6. Thebioreactor of claim 5, wherein the base of the stand is polygonal inshape and has a maximum cross-sectional dimension that is smaller than amaximum diameter of the separator structure, such that the separatorstructure is configured to be seated into the stand.
 7. The bioreactorof claim 1, wherein the effluent outlet comprises a weir configured toprevent solid matter from entering into the effluent outlet.
 8. Thebioreactor of claim 1, wherein the tank is configured for above-grounduse.
 9. The bioreactor of claim 8, wherein the bioreactor is configuredto be positioned in a mobile container, such that the bioreactor ismobile.
 10. The bioreactor of claim 1, wherein the separator structurecomprises an inlet opening positioned above the downwardly-facingopening and proximal to a top of the separator structure, but below theeffluent outlet, the interior of the separator structure communicatingwith the tank external to the separator structure via the inlet opening.11. A water treatment system, comprising: a bioreactor comprising: atank configured to receive an influent liquid; a separator structurepositioned in the tank, the separator structure having a frustoconicalshape and defining a downwardly-facing opening proximal to or at abottom of the separator structure, wherein an interior of the separatorstructure is in communication with the tank, external to the separatorstructure, at least via the opening; an aeration vent positionedproximal to a bottom of the tank and configured to direct air into thetank, but not directly into the interior of the separator structure; andan effluent outlet communicating with the interior of in the separatorstructure, proximal to a top of the separator structure, wherein arelatively clean effluent liquid, in comparison to the influent liquid,exits from the separator structure via the effluent outlet; a filtertank in fluid communication with the effluent outlet of the tank; anultraviolet (UV) filter in fluid communication with the filter tank; anda chlorinator in fluid communication with the UV filter.
 12. The systemof claim 11, further comprising: a second tank and a second separatorstructure positioned at least partially in the second tank, the secondtank being in communication with the effluent outlet of the bioreactorand the filter tank; and a transfer tank in fluid communication with thechlorinator.
 13. The system of claim 12, further comprising a singlecontainer, wherein the bioreactor, second clarifier, filter tank, UVfilter, chlorinator, and transfer tank are positioned within the singlecontainer, and wherein the single container is configured to be movedbetween well sites.
 14. The system of claim 12, wherein the effluentliquid is not pumped between the second tank and the transfer tank, butis moved by gravity.
 15. The system of claim 11, wherein the bioreactorfurther comprises an aeration line connected to the aeration vent,wherein the aeration line extends along a bottom of the tank.
 16. Thesystem of claim 15, wherein the aeration line extends through a wall ofthe tank, proximal to the bottom of the tank, and wherein the aerationvent is not positioned directly below the separator structure.
 17. Thesystem of claim 15, wherein the aeration vent comprises one or morediffusers extending from the bottom of the tank.
 18. The system of claim15, wherein the bioreactor further comprises a stand having a baseconfigured to receive the separator structure, and wherein the stand issupported on a bottom of the tank.
 19. The system of claim 18, whereinthe base of the stand is polygonal in shape and has a maximumcross-sectional dimension that is smaller than a maximum diameter of theseparator structure, such that the separator structure is configured tobe seated into the stand.
 20. The system of claim 11, wherein theseparator structure occupies a volume that is less than about ⅛^(th) ofa volume of the tank.